Digital data storage media often store data in an encoded format such that the data can be recovered from the media via a transducer and recovery signal processing electronics.
A particularly useful type of storage medium is an optical disc, which is generally portable in nature and can store any number of different types of data such as video, audio, computer ROM, etc. Optical discs are often commercially offered in accordance with industry proposed standards, such as DVD, DVD-HD, Blu-Ray, Mini-Disc, CD, CD-ROM, etc. Optical discs can further be pre-recorded or recordable (once or many times), and can have single or multiple data storage layers.
Generally, pre-recorded optical discs are formed using an injection molding or similar “pressing” operation whereby a series of pits and lands are formed along a number of tracks (one continuous spiral, a number of discrete concentric rings, etc.). The elevational difference between the pits and lands is selected to provide different effective reflectivities therebetween, allowing the transducer to detect each pit/land transition and form the readback signal therefrom.
Recordable optical discs are often configured such that localized areas on the disc undergo a spectral transformation during recording to provide areas of different reflective characteristics that function in a manner similar to the pits and lands in a recorded disc.
It is sometimes desirable to provide human readable information on a portion of an optical disc or other medium. This human readable information, sometimes referred to as a “watermark,” can include graphics, title or content information, processing information, machine readable information (OCR, barcodes, etc.), and so on.
There have been a number of techniques proposed in the art to provide such information on a medium. Nevertheless, with the continued consumer demand for digital content from storage media (particularly optical discs), there remains a continual need for improvements in the manner in which such information can be provided. It is to these and other improvements that the present invention is generally directed.